Various rollover detection methodologies have been developed for activating electrically deployed rollover safety devices such as air bags, side curtains, seat belt pretensioners and pop-up roll bars, and/or for activating visual, auditory or haptic warnings. Typical parameters used to detect rollover include the vehicle attitude rate of change or angular roll rate, the vehicle roll angle, the vehicle speed, the steering wheel angle, the vehicle yaw rate and the side-slip angle. For example, the U.S. Pat. No. 6,542,792 to Schubert et al., issued on Apr. 1, 2003, discloses a rollover detection algorithm that involves determining an angular roll rate vs. roll angle operating point of the vehicle, and comparing the determined operating point to one or more calibrated thresholds.
While algorithms such as the one disclosed in the aforementioned U.S. Pat. No. 6,542,792 to Schubert et al. can timely detect impending rollover events that occur relatively quickly with high roll rates, soil trip rollover events that occur when a vehicle slides sideways into soft or yielding roadside material such as soil, sand or gravel can be very difficult to detect in a timely fashion. Accordingly, what is needed is a method of reliably and timely detecting soil trip rollover events.